Laparoscopic surgery, performed through very small incisions in the patient, has markedly lessened patient trauma and hospitalization time. In performing laparoscopic surgery it is often desirable to apply internal gas pressure, usually carbon dioxide or argon gas to expand the working space. Such gas expansion procedure is referred to as insufflation, and the pressure within the insufflated space must be controlled quite precisely. The instruments for introducing and releasing gas are known as trochars, and are essentially hollow spikes which are stabbed through the patient's epidermis and into the working area. Too much pressure can cause obvious damage, while too little pressure can allow the pointed tips of the trochars to engage internal organs with consequent damage.
Commercial insufflators generally have some means for measuring internal pressure, and often for automatic regulation of pressure. However, such pressure has generally been controlled by analog devices which inprecise in nature.